Apparatus and method for supporting data stream multiplexing in internet protocol multimedia subsystem-data channel service

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting higher data transmission rates. According to one embodiment of the present disclosure, a method of a proxy-call state control function (P-CSCF) entity in an internet protocol (IP) multimedia subsystem-data channel (IMS-DC) service may comprise the steps of: receiving, from a user equipment (UE), a data channel session connection request message including session description protocol (SDP) offer information, the SDP offer information including multiplexing support information; determining, on the basis of the multiplexing support information, whether to support multiplexing; and transmitting, to an IMS application gateway (AGW) entity, a request for data stream-related information including the multiplexing support information.

Description

Device and method for supporting data stream multiplexing in Internet Protocol Multimedia Subsystem-Data Channel Service

[0001] The present disclosure relates to an IMS-DC (IP (internet protocol) Multimedia Subsystem Data Channel) service, and more particularly, to a method and device for supporting data stream multiplexing during a bootstrap data channel setup signaling procedure and / or an application data channel setup signaling procedure for connecting an IMS-DC service.

[0002] 5G mobile communication technology defines a wide frequency band to enable fast transmission speeds and new services, and can be implemented not only in the sub-6GHz frequency band such as 3.5 gigahertz (3.5GHz), but also in the ultra-high frequency band called millimeter wave (mmWave) such as 28GHz and 39GHz ('Above 6GHz'). In addition, for 6G mobile communication technology, which is called the system after 5G communication (Beyond 5G), implementation in the terahertz band (for example, the 3 terahertz (3THz) band at 95GHz) is being considered to achieve a transmission speed that is 50 times faster than 5G mobile communication technology and an ultra-low latency time that is reduced to one-tenth.

[0003] In the early stages of 5G mobile communication technology, the goal is to support services and satisfy performance requirements for enhanced Mobile Broadband (eMBB), Ultra-Reliable Low-Latency Communications (URLLC), and massive Machine-Type Communications (mMTC). These include beamforming and massive MIMO to mitigate path loss of radio waves in ultra-high frequency bands and increase the transmission distance of radio waves, support for various numerologies (such as operation of multiple subcarrier intervals) and dynamic operation of slot formats for efficient use of ultra-high frequency resources, initial access technology to support multi-beam transmission and wideband, definition and operation of BWP (Bidth Part), new channel coding methods such as LDPC (Low Density Parity Check) codes for large-capacity data transmission and Polar Code for reliable transmission of control information, and L2 pre-processing (L2). Standardization has been made for network slicing, which provides dedicated networks specialized for specific services, and pre-processing.

[0004] Currently, discussions are underway to improve and enhance the initial 5G mobile communication technology in consideration of the services that 5G mobile communication technology was intended to support, and physical layer standardization is in progress for technologies such as V2X (Vehicle-to-Everything) to help autonomous vehicles make driving decisions and increase user convenience based on their own location and status information transmitted by vehicles, NR-U (New Radio Unlicensed) for the purpose of system operation that complies with various regulatory requirements in unlicensed bands, NR terminal low power consumption technology (UE Power Saving), Non-Terrestrial Network (NTN), which is direct terminal-satellite communication to secure coverage in areas where communication with terrestrial networks is impossible, and Positioning.

[0005] In addition, standardization of wireless interface architecture / protocols is in progress for technologies such as intelligent factories (Industrial Internet of Things, IIoT) to support new services through linkage and convergence with other industries, Integrated Access and Backhaul (IAB) that provides nodes for expanding network service areas by integrating wireless backhaul links and access links, Mobility Enhancement technology including Conditional Handover and Dual Active Protocol Stack (DAPS) handover, and 2-step random access (2-step RACH for NR) that simplifies random access procedures. Standardization is also in progress for system architecture / services such as 5G baseline architecture (e.g., Service-based Architecture, Service-based Interface) for grafting Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC) that provides services based on the location of the terminal.

[0006] Once these 5G mobile communication systems are commercialized, an explosive increase in connected devices will be connected to the communication network, necessitating enhanced functionality and performance of 5G mobile communication systems and integrated operation of these connected devices. To this end, new research will be conducted on improving 5G performance and reducing complexity, supporting AI services, supporting metaverse services, and drone communications by utilizing eXtended Reality (XR), Artificial Intelligence (AI), and Machine Learning (ML) to efficiently support Augmented Reality (AR), Virtual Reality (VR), and Mixed Reality (MR).

[0007] In addition, the development of these 5G mobile communication systems includes new waveforms to ensure coverage in the terahertz band of 6G mobile communication technology, multi-antenna transmission technologies such as Full Dimensional MIMO (FD-MIMO), Array Antenna, and Large Scale Antenna, metamaterial-based lenses and antennas to improve the coverage of terahertz band signals, high-dimensional spatial multiplexing technology using Orbital Angular Momentum (OAM), Reconfigurable Intelligent Surface (RIS) technology, as well as full duplex technology to improve the frequency efficiency and system network of 6G mobile communication technology, satellite, AI (Artificial Intelligence) from the design stage and AI-based communication technology that realizes system optimization by internalizing end-to-end AI support functions, and ultra-high-performance communication and computing resources to provide services with complexity that exceeds the limits of terminal computing capabilities. It can serve as a basis for the development of next-generation distributed computing technologies that can be realized by utilizing them.

[0008] The IMS system is a system for transmitting IP-based multimedia. Various services, such as VoLTE and VoNR, are provided through existing IMS networks linked to LTE or 5G networks. The purpose of the IMS data channel is to provide various value-added services, such as user location information transmission and screen sharing, using separate applications, in addition to the basic voice or video-based services, by utilizing the IMS-DC service, a data channel linked to the IMS, in addition to existing RTP-based voice, video, and text services. To transmit these value-added services using the data channel within the IMS data network, the terminal transmits signaling information for the data channel-based service to the network through a bootstrap data channel connection process. The network then transmits application information to the terminal based on user or service provider settings and request information received from the terminal, enabling the terminal to download the application for a specific service. The terminal can then request and receive the application based on this information. Furthermore, the network can allocate a separate media function entity within the network to receive data for the application and perform media resource management service operations that connect this entity to a data channel application server.

[0009] The present disclosure provides a method and device for transmitting information to a media function entity or IMS-AGW to support multiplexing of data streams according to service requirements of a terminal or service provider during a bootstrap or application data channel connection process for using an IMS data channel service.

[0010] According to one embodiment of the present disclosure, a method of a P-CSCF (proxy - call state control function) entity in an IMS-DC (Internet Protocol (IP) multimedia subsystem-data channel) service includes the steps of: receiving a data channel session connection request message including session description protocol (SDP) offer information from a UE (user equipment), wherein the SDP offer information includes multiplexing support information; determining whether multiplexing is supported based on the multiplexing support information; and transmitting a request for data stream related information including the multiplexing support information to an IMS-AGW (application gateway) entity.

[0011] According to one embodiment of the present disclosure, a method of an IMS-AGW (application gateway) entity in an IMS-DC (internet protocol) multimedia subsystem-data channel) service includes the step of receiving a request for data stream related information including multiplexing support information from a P-CSCF (proxy - call state control function) entity, wherein the multiplexing support information is based on a data channel session connection request message including session description protocol (SDP) offer information received from a UE (user equipment).

[0012] According to one embodiment of the present disclosure, in an IMS-DC (Internet Protocol (IP) multimedia subsystem-data channel) service, a P-CSCF (proxy - call state control function) entity includes a transceiver; and at least one processor; wherein the at least one processor is configured to receive, from a user equipment (UE), a data channel session connection request message including session description protocol (SDP) offer information, wherein the SDP offer information includes multiplexing support information, determine whether multiplexing is supported based on the multiplexing support information, and transmit a request for data stream related information including the multiplexing support information to an IMS-AGW (application gateway) entity.

[0013] According to one embodiment of the present disclosure, in an IMS-DC (IP (internet protocol) multimedia subsystem-data channel) service, an IMS-AGW (application gateway) entity includes a transceiver; and at least one processor; wherein the at least one processor is configured to receive a request for data stream related information including multiplexing support information from a P-CSCF (proxy - call state control function) entity, wherein the multiplexing support information is based on a data channel session connection request message including session description protocol (SDP) offer information received from a UE (user equipment).

[0014] A method and device according to one embodiment of the present disclosure can perform a bootstrap or application data channel setup process for generating and transmitting information to support discovery and multiplexing of a media function entity or an IMS-AGW entity based on service requirements and network information of a UE and a service provider for setup of an IMS-DC service that supports multiplexing of data streams.

[0015] FIG. 1 is a diagram illustrating a network structure and interface of a 5G system according to one embodiment of the present disclosure.

[0016] FIG. 2 is an example of an IMS-DC (IP (internet protocol) multimedia subsystem data channel) structure that provides a data channel service based on an IMS (IP (internet protocol) multimedia subsystem) service according to one embodiment of the present disclosure.

[0017] FIG. 3a, FIG. 3b, and FIG. 3c are flowcharts illustrating a bootstrap data channel setup signaling procedure for an IMS-DC (Internet Protocol (IP) multimedia subsystem data channel) service connection request and related application download in a UE according to one embodiment of the present disclosure.

[0018] FIG. 4 is a flowchart illustrating the operation of a P-CSCF for supporting a multiplexing-based application data channel service when requesting it during an application data channel setup signaling procedure in a UE according to one embodiment of the present disclosure.

[0019] FIG. 5 is a flowchart for explaining an application data channel setup signaling process according to the connection type of the application data channel in an IMS AS (IP (internet protocol) multimedia subsystem application server) according to one embodiment of the present disclosure.

[0020] FIG. 6 is a flowchart for explaining an application data channel setup signaling process according to the connection type of the application data channel in an IMS AS (IP (internet protocol) multimedia subsystem application server) according to one embodiment of the present disclosure.

[0021] FIG. 7 is a flowchart for explaining an application data channel setup signaling process according to the connection type of the application data channel in an IMS AS (IP (internet protocol) multimedia subsystem application server) according to one embodiment of the present disclosure.

[0022] FIG. 8A and FIG. 8B are flowcharts illustrating an application data channel setup signaling process for transmitting related information for application data channel connection to a remote network in an IMS AS (IP (internet protocol) multimedia subsystem application server) according to one embodiment of the present disclosure and receiving a requested result from the remote network.

[0023] FIG. 9 is an example of SDP offer and SDP answer information transmitted from a session request and response message that supports multiplexing for an application data channel connection request in a terminal according to an embodiment of the present invention.

[0024] FIG. 10 is a structural diagram illustrating the structure of a network entity according to one embodiment of the present disclosure.

[0025] Hereinafter, one embodiment of the present disclosure will be described in detail with reference to the attached drawings.

[0026] In describing this disclosure, descriptions of technical details that are well-known in the technical field to which this disclosure pertains and are not directly related to this disclosure will be omitted. This is to avoid obscuring the gist of this disclosure by omitting unnecessary explanations and to convey it more clearly. Furthermore, the terms described below are defined based on their functions in this disclosure and may vary depending on the intent or custom of the user or operator. Therefore, their definitions should be based on the overall content of this specification.

[0027] For the same reason, some components in the attached drawings are exaggerated, omitted, or schematically depicted. Furthermore, the dimensions of each component do not entirely reflect its actual size. Identical or corresponding components in each drawing are assigned the same reference numbers.

[0028] Hereinafter, a base station (BS) is an entity that performs resource allocation of a terminal, and may be at least one of a gNode B, an eNode B, a Node B (or an xNode B (where x is an alphabet including g or e)), a wireless access unit, a base station controller, a satellite, an airborn, or a node on a network. A user equipment (UE) may include a mobile station (MS), a vehicle, a satellite, an airborn, a cellular phone, a smartphone, a computer, or a multimedia system capable of performing a communication function. In the present disclosure, a downlink (DL) is a wireless transmission path of a signal transmitted from a base station to a terminal, and an uplink (UL) means a wireless transmission path of a signal transmitted from a terminal to an air station. Additionally, a sidelink (SL) may exist, which means a wireless transmission path of a signal transmitted from a terminal to another terminal.

[0029] In addition, although LTE, LTE-A, or 5G systems may be described below as examples, embodiments of the present disclosure may also be applied to other communication systems having similar technical backgrounds or channel types. For example, this may include 5G-Advance or NR-Advance, or 6th generation mobile communication technology (6G) developed after 5G mobile communication technology (or new radio, NR), and the 5G described below may also include existing LTE, LTE-A, and other similar services. In addition, the present disclosure may be applied to other communication systems with some modifications within a range that does not significantly deviate from the scope of the present disclosure, as determined by a person having skilled technical knowledge.

[0030] At this time, it will be understood that each block of the processing flowchart drawings and combinations of the flowchart drawings can be performed by computer program instructions. These computer program instructions can be installed in a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, so that the instructions executed by the processor of the computer or other programmable data processing equipment create a means for performing the functions described in the flowchart block(s). These computer program instructions can also be stored in a computer-available or computer-readable memory that can direct a computer or other programmable data processing equipment to implement the functions in a specific manner, so that the instructions stored in the computer-available or computer-readable memory can also produce a manufactured item that includes an instruction means for performing the functions described in the flowchart block(s). Since the computer program instructions may be installed on a computer or other programmable data processing device, a series of operational steps may be performed on the computer or other programmable data processing device to create a computer-executable process, and the instructions that cause the computer or other programmable data processing device to perform the steps for performing the functions described in the flowchart block(s) may also provide steps for performing the functions described in the flowchart block(s).

[0031] Additionally, each block may represent a module, segment, or portion of code that contains one or more executable instructions for performing a specific logical function(s). It should also be noted that in some alternative implementation examples, the functions described in the blocks may occur out of order. For example, two blocks depicted in succession may actually be executed substantially concurrently, or the blocks may sometimes be executed in reverse order, depending on their respective functions.

[0032] Here, the term '~ part' used in this embodiment means software or hardware components such as FPGA (Field Programmable Gate Array) or ASIC (Application Specific Integrated Circuit), and the '~ part' performs certain roles. However, the '~ part' is not limited to software or hardware. The '~ part' may be configured to be on an addressable storage medium or may be configured to play one or more processors. Therefore, as an example, the '~ part' includes components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided within the components and '~ parts' may be combined into a smaller number of components and '~ parts' or further separated into additional components and '~ parts'. Additionally, the components and '~parts' may be implemented to activate one or more CPUs within a device or secure multimedia card. In addition, in an embodiment, the '~parts' may include one or more processors.

[0033] 3GPP, responsible for cellular mobile communications standards, is standardizing a new core network architecture called 5G Core (5GC) to facilitate the evolution of 4G LTE systems to 5G systems. Compared to the Evolved Packet Core (EPC), the network core for 4G, 5GC supports the following differentiated features:

[0034] 5GC introduces the Network Slice feature. As a requirement of 5G, 5GC must support a variety of terminal types and services, such as enhanced Mobile Broadband (eMBB), Ultra Reliable Low Latency Communications (URLLC), and massive Machine Type Communications (mMTC). These terminals and services each have different requirements for the core network. For example, eMBB services may require high data rates, while URLLC services may require high reliability and low latency. To meet these diverse service requirements, Network Slice technology has been proposed.

[0035] Network slicing can refer to a method of virtualizing a single physical network to create multiple logical networks (e.g., network slices). An activated network slice can be called a network slice instance, and each network slice instance (NSI) can have different characteristics. By configuring a network function (NF) for each NSI according to its characteristics, mobile carriers can satisfy various service requirements according to terminals / services. For example, mobile carriers can efficiently support various 5G services (e.g., eMBB, URLLC, or mMTC) by allocating an NSI that matches the characteristics of the service required for each terminal.

[0036] 5GC can easily support the network virtualization paradigm by separating mobility management functions from session management functions. In 4G LTE, all terminals can receive services from the network through signaling exchanges with a single core entity called the mobility management entity (MME), which is responsible for registration, authentication, mobility management, and session management. In 5G, the number of terminals (including MTC terminals) will explode, and the mobility and traffic / session characteristics that must be supported depending on the terminal type will become more specialized. Therefore, supporting all functions from a single entity (such as the MME) will inevitably reduce scalability by adding entities for each required function. Therefore, various functions are being developed based on a structure that separates mobility management and session management functions to improve scalability in terms of functional / implementation complexity and signaling load of the core entity responsible for the control plane.

[0037] Interactive services require very low latency to support two-way communication, and additional requirements arise when used for content transmission for interactive services to improve accessibility as mentioned above. In the present disclosure, in order to use a service utilizing a data channel-based application requiring very low latency, a terminal or a service provider server provides a low latency value required for providing the service to the network when requesting a service connection, and the network can provide a function to search for and select an appropriate media function entity based on the required latency value when connecting a bootstrap data channel of a service utilizing the data channel-based application.

[0038] The present disclosure introduces a method for establishing a connection for a service utilizing a data channel-based application requiring very low latency, and a process for performing a connection operation between network entities to provide low latency through a boostslack data channel setup signaling process based on the related information by transmitting related parameters to a network. When the information is transmitted in the 3gpp-hint-qos field for low latency requirements within the session initiation protocol (SIP) or when an application server registers the data channel-related information with a data channel signaling function entity within a data channel server, low latency information required for using the application-related service can be registered together. An IMS AS that has received the above information can utilize the related information when searching for a network function entity to select a media function entity that takes end-to-end delay into account based on service requirements. Additionally, when registering a network function within the NRF of a media function entity, related information can be additionally included in the media profile to support discovery of the network function entity based on the low latency requirement in IMS AS, etc., and selection of the media function entity based on the information.

[0039] In order to support transmission / reception operations through data streams using a single port in a UE for multiple applications and multiple streams transmitted from a data channel application server and a remote UE, a media resource management service operation can be performed to support multiplexing of data streams through a media function entity in the network or IMS-AGW. In addition, the UE can transmit a request for application-related information supporting multiplexing to the network through a bootstrap data channel setup process, and the network that receives the request can support a service supporting multiplexing by transmitting an application list including application information supporting multiplexing to the UE.

[0040] FIG. 1 is a diagram illustrating a network structure and interface of a 5G system according to one embodiment of the present disclosure.

[0041] A network entity included in the network structure of the 5G system of Fig. 1 may include a network function (NF) depending on the system implementation.

[0042] Referring to FIG. 1, the network structure of a 5G system may include various network entities. For example, the 5G system may include an authentication server function (AUSF) entity (108), an access and mobility management function (AMF) entity (103), a session management function (SMF) entity (105), a policy control function (PCF) entity (106), an application function (AF) entity (107), a unified data management (UDM) entity (109), a data network (DN) (110), a network exposure function (NEF) entity (111), a network slicing selection function (NSSF) entity (114), a network repository function (NRF) entity (115), a network data analytics function (NWDAF), and an edge application service domain repository (EDS). It may include a domain repository (EDR), an edge application server (EAS), an EAS discovery function (EASDF), a user plane function (UPF) entity (104), a (radio) access network ((R)AN) (102), and a terminal, for example, a user equipment (UE) (101).

[0043] Each NF entity of the 5G system (100) supports the following functions.

[0044] AUSF (108) processes and stores data for authentication of UE (101).

[0045] AMF (103) provides functions for access and mobility management per UE, and one UE can be connected to one AMF by default. Specifically, the AMF (103) provides signaling between CN nodes for mobility between 3GPP access networks, termination of a radio access network (RAN) CP interface (i.e., N2 interface), termination of non-access stratum (NAS) signaling (N1), NAS signaling security (NAS ciphering and integrity protection), AS security control, registration management (registration area management), connection management, idle mode UE reachability (including control and performance of paging retransmission), mobility management control (subscription and policy), intra-system mobility and inter-system mobility support, support for network slicing, SMF selection, lawful intercept (for AMF events and interfaces to the LI system), provision of forwarding of session management (SM) messages between UE and SMF, transparent proxy for SM message routing, access authentication, access authorization including roaming authorization check. It supports functions such as authorization, provision of SMS message transmission between UE and SMSF, security anchor function (SAF) and / or security context management (SCM). Some or all of the functions of an AMF entity (103) may be supported within a single instance of an AMF entity.

[0046] DN (110) refers to, for example, an operator service, Internet access, or a third-party service. DN (110) transmits a downlink protocol data unit (PDU) to the UPF entity (104) or receives a PDU transmitted from the UE (101) from the UPF entity (104).

[0047] The PCF entity (106) receives information about packet flows from the application server and provides a function to determine policies such as mobility management and session management. Specifically, the PCF entity (106) supports functions such as supporting a unified policy framework for controlling network operations, providing policy rules so that control plane function entity(ies) (e.g., AMF entity, SMF entity, etc.) can enforce the policy rules, and implementing a front end for accessing related subscription information for policy determination within a user data repository (UDR).

[0048] The SMF entity (105) provides a session management function, and when the UE (101) has multiple sessions, each session can be managed by a different SMF entity. Specifically, the SMF entity (105) is responsible for session management (e.g., session establishment, modification, and termination, including tunnel maintenance between the UPF entity (104) and the (R)AN (102) node), UE IP address allocation and management (optionally including authentication), selection and control of UP functions, setting up traffic steering to route traffic from the UPF entity (104) to the appropriate destination, termination of the interface to policy control functions, enforcement of the control portion of policy and quality of service (QoS), lawful intercept (for SM events and interfaces to the LI system), termination of the session management (SM) portion of NAS messages, downlink data notification, initiation of AN (access network) specific SM information (delivered to the (R)AN (102) via N2 via the AMF entity (103)), determination of the session and service continuity (SSC) mode of the session, and roaming. Supports functions such as functions, etc. Some or all functions of an SMF entity (105) can be supported within a single instance of an SMF entity.

[0049] The UDM entity (109) stores user subscription data, policy data, etc. The UDM entity (109) includes two parts: an application front end (FE) and a user data repository (UDR).

[0050] The FE (front end) includes the UDM FE, which is responsible for location management, subscription management, and credential processing, and the PCF entity, which is responsible for policy control. The UDR stores the data required for the functions provided by the UDM-FE and the policy profiles required by the PCF entity. The data stored in the UDR includes user subscription data and policy data, including subscription identifiers, security credentials, access and mobility-related subscription data, and session-related subscription data. The UDM-FE accesses the subscription information stored in the UDR and supports functions such as authentication credential processing, user identification handling, access authentication, registration / mobility management, subscription management, and SMS management.

[0051] The UPF entity (104) forwards the downlink PDU received from the DN (110) to the UE (101) via the (R)AN (102), and forwards the uplink PDU received from the UE (101) via the (R)AN (102) to the DN (110). Specifically, the UPF entity (104) supports functions such as an anchor point for intra / inter RAT mobility, an external PDU session point for interconnection to the Data Network, a user plane part of packet routing and forwarding, packet inspection and policy rule enforcement, an uplink classifier to support lawful intercept, traffic usage reporting, routing of traffic flows to the Data Network, a branching point to support multi-homed PDU sessions, QoS handling for the user plane (e.g., packet filtering, gating, uplink / downlink rate enforcement), uplink traffic validation (service data flow (SDF) to QoS flow mapping), transport level packet marking in uplink and downlink, downlink packet buffering and downlink data notification triggering. Some or all of the functions of a UPF entity (104) may be supported within a single instance of a UPF.

[0052] The AF entity (107) interacts with the 3GPP core network to provide services (e.g., supporting functions such as application impact on traffic routing, access to network capability exposure, and interaction with the policy framework for policy control).

[0053] (R)AN(102) is a general term for a new radio access network that supports both evolved E-UTRA, an evolved version of 4G radio access technology, and new radio (NR) (e.g., gNB).

[0054] The gNB provides functions for radio resource management (i.e., radio bearer control, radio admission control, connection mobility control, dynamic allocation of resources to the UE in uplink / downlink (i.e., scheduling), IP (internet protocol) header compression, encryption and integrity protection of user data streams, selection of an AMF upon attachment of the UE if routing to the AMF is not determined from the information provided to the UE, routing of user plane data to UPF(s), routing of control plane information to the AMF, connection setup and teardown, scheduling and transmission of paging messages (originating from the AMF), scheduling and transmission of system broadcast information (originating from the AMF or operating and maintenance (O&M)), measurement and measurement reporting setup for mobility and scheduling, transport level packet marking in uplink, session management, support for network slicing, and QoS flows. It supports features such as mapping to management and data radio bearers, support for UEs in inactive mode, distribution of NAS messages, NAS node selection, radio access network sharing, dual connectivity, and tight interworking between NR and E-UTRA.

[0055] UE (101) refers to a user equipment. The user equipment may be referred to by terms such as terminal, mobile equipment (ME), or mobile station (MS). Furthermore, the user equipment may be a portable device such as a laptop, mobile phone, personal digital assistant (PDA), smartphone, or multimedia device, or may be a non-portable device such as a personal computer (PC) or vehicle-mounted device.

[0056] The NEF (111) provides a means to securely expose services and capabilities provided by 3GPP network functions, for example, for third parties, internal exposure / re-exposure, application functions, and edge computing. The NEF (111) receives information from other NF (s) (based on the exposed capability(s) of other NF (s)). The NEF (111) can store the received information as structured data using a standardized interface to a data storage network function. The stored information can be re-exposed to other NF entity(s) and AF entity(s) by the NEF entity (111) and used for other purposes, such as analysis.

[0057] EASDF is an NF that can add an ECS (EDNS (extension mechanisms for DNS) client subnet) option that can be expressed as the address of a DNS server to which a DNS (domain name system) request of a terminal will be forwarded, and an IP subnet address to be added when forwarding a DNS request of the terminal, for each FQDN (fully qualified domain name). EASDF receives EAS (exchange active sync) domain configuration information from EDR, and processes a DNS request message received from a terminal according to the received information. In addition, EASDF is an NF that receives a terminal IP address, location information of the terminal within 3GPP, DNS message processing rules, and DNS message reporting rules from the SMF (105), processes a DNS Query message received from the terminal, a DNS response message received from a DNS server, and transmits information in a DNS message and statistical information processed therefrom to the SMF (105) according to the DNS message reporting rules.

[0058] NRF (115) supports service discovery. It receives NF discovery requests from NF instances and provides information about discovered NF instances to the NF instances. It also maintains available NF instances and the services they support.

[0059] Meanwhile, for convenience of explanation, FIG. 1 illustrates a reference model for a case where a UE (101) accesses one DN (110) using one PDU session, but the present disclosure is not limited thereto.

[0060] A UE (101) can access two (i.e., local and central) data networks simultaneously using multiple PDU sessions. In this case, two SMFs can be selected for different PDU sessions. However, each SMF can have the ability to control both the local UPF and the central UPF within the PDU session.

[0061] Additionally, the UE (101) may simultaneously access two (i.e., local and central) data networks provided within a single PDU session.

[0062] In the 3GPP system, a conceptual link connecting NFs within a 5G system is defined as a reference point. For example, the reference point(s) included in the 5G system (100) of FIG. 1 are as follows.

[0063] - N1: Reference point between UE (101) and AMF (103)

[0064] - N2: Reference point between (R)AN(102) and AMF(103)

[0065] - N3: Reference point between (R)AN(102) and UPF(104)

[0066] - N4: Reference point between SMF (105) and UPF (104)

[0067] - N5: Reference point between PCF (106) and AF (107)

[0068] - N6: Reference point between UPF (104) and DN (110)

[0069] - N7: Reference point between SMF (105) and PCF (106)

[0070] - N8: Reference point between UDM (109) and AMF (103)

[0071] - N10: Reference point between UDM (109) and SMF (105)

[0072] - N11: Reference point between AMF (103) and SMF (105)

[0073] - N12: Reference point between AMF (103) and AUSF (108)

[0074] - N13: Reference point between UDM (109) and AUSF (108)

[0075] - N14: Reference point between two AMFs (103)

[0076] - N15: Reference point between PCF and AMF in non-roaming scenario, reference point between PCF and AMF in visited network in roaming scenario.

[0077] - Nx: Reference point between SMF(105) and EASDF

[0078] - Ny: Reference point between NEF (EDF) (111) and EASDF

[0079] FIG. 2 is an example of an IMS-DC (IP (internet protocol) multimedia subsystem data channel) structure that provides a data channel service based on an IMS (IP (internet protocol) multimedia subsystem) service according to one embodiment of the present disclosure.

[0080] In the above structure, the terminal can transmit a SIP (session initiation protocol) INVITE message to an existing CSCF, such as a P-CSCF (proxy - call session control function) and an S-SCSF (serving - call session control function), to request a call session connection. The SIP INVITE message can include media-related parameters and multiplexing-related requirement information in the SDP (Session Description Protocol) and transmit them together to the network. In addition, the terminal can transmit an SDP offer including bootstrap information together with an SDP offer for connecting an existing video or audio session, in the SIP INVITE message, in order to use an IMS data channel service.

[0081] The S-CSCF, which receives the SIP INVITE including the above SDP information, can forward the contents of the bootstrap data channel SDP offer to the IMS AS if the SIP INVITE contains a bootstrap data channel SDP offer for a data channel service connection request. At this time, the S-CSCF checks whether the terminal or network supports IMS-DC based on the contents of the received bootstrap-related SDP offer. If both sides support the data channel, the S-CSCF can decide to forward the information for the bootstrap data channel connection for the data channel connection to the IMS AS. The IMS AS, which receives the bootstrap-related SDP offer message from the S-CSCF, can first check with the HSS (home subscriber server) whether the UE or subscriber can use the data channel service. If the user cannot use the data channel based on the user profile of the user, the MMTel (multimedia telephony) session setup operation can be performed without connecting the data channel through the general IMS process. Additionally, if the user cannot use a data channel-based service, the IMS AS can update the SIP INVITE message received from the S-CSCF by deleting the DC (data channel)-related media information in the SIP INVITE message, and then forward the updated SIP INVITE message to the S-CSCF.

[0082] If the service user can use the service based on the IMS data channel, data channel bootstrapping can be performed through a data channel call request with the Data Channel Signaling Function (DCSF). The IMS AS can select a DCSF by performing discovery and selection of a DCSF instance from the NRF based on the local configuration of the network operator or information transmitted from the UE. The IMS AS can transmit a Session Event Control Notification (SessionEventControl_Notify) message containing information such as SessionEstablishmentRequestEvent, Session ID, CallingID, CalledID, SessionCase, Event initiator, MediaInfoList, and DC Stream ID to the DCSF selected through the above process.

[0083] Upon receiving a DC control request from an IMS AS, the DCSF can make policy decisions on how to create a bootstrap data channel based on the relevant parameters in the DC control request message. Furthermore, the DCSF can determine MDC1 media information to enable the UE to download applications via the MF or MRF.

[0084] Based on the above decision information, DCSF can forward a MediaControl_MediaInstruction message containing information such as SessionID and MediaInstructionSet to the IMS AS. DCSF can also forward the MediaInstructionSet to the IMS AS, including the MDC1 media endpoint address, DC stream ID, and alternative information such as the URL of the application list transmitted on the MDC1 interface. Based on this, DCSF can provide the IMS AS with a policy on how to create a bootstrap data channel using MF on the originating and terminating sides.

[0085] IMS AS can select MF through a process of searching and selecting MF instance or enhanced MRF supporting local configuration or DC media capabilities using NRF.

[0086] The IMS AS can forward a list of Media Termination Descriptors to the MF selected in the above process via the Nmf_MRM_Create message. The IMS AS can request the creation of two different Media Terminations. One Media Termination may represent local bootstrap media-related information, and the other may represent remote bootstrap media-related information to be provided to a remote UE. Each Media Termination may include resource allocation request information for the Mb and MDC1 interfaces. The MF may forward the results of the negotiation of the corresponding data channel media resource information to the IMS AS.

[0087] An IMS AS may send a response to a MediaInstruction request from the DCSF. The response message may include information regarding the result of the above operation and information regarding the MDC1 data channel media resource information negotiation.

[0088] DCSF can store media resource information in a response message to a MediaInstruction request received from an IMS AS and forward a response message related to a data channel connection notification (SessionEventControl_Notify) request from the IMS AS to the IMS AS.

[0089] The IMS AS can forward a SIP INVITE message containing an updated SDP offer with media information from the MF or enhanced MRF to the S-CSCF. The S-CSCF can forward the SIP INVITE message containing the received updated SDP offer to the remote network and UE#2.

[0090] UE#2 and the terminating network can forward the SDP response related to the bootstrap data channel to the originating network in an 18X response message. Based on the received SDP response message, the MF or enhanced MRF can update the data channel media resource information of UE#2. Afterwards, UE#2 and the terminating network can send a 200 OK response message indicating the successful completion of the request.

[0091] The IMS AS can notify the DCSF of successful session connection-related event information by sending a SessionEventControl Notify message containing SessionEstablishmentSuccessEvent, SessionID, and MediaInfoList. After receiving a response message for the successful session connection event notification from the DCSF, the IMS AS can send a 200 OK message to UE#1, indicating that the bootstrap data channel has been connected. This allows the bootstrap data channel connection to be established between UE#1, UE#2, and the originating MF or enhanced MRF. Afterwards, UE#1 and UE#2 can request data channel applications by sending an application request message to the MF or enhanced MRF. If the multi-DC application supports it, the application list can be requested. The MF or MRF can change the root URL to application-related URL information based on the replacement URL information received from the DCSF. Afterwards, the MF can forward the application request message received from the UE to the DCSF. DCSF can provide a list of applications or appropriate data applications to UE#1 and UE#2, depending on the UE's data channel processing capabilities and selection. Depending on the MF's location, if terminating MF or MRF is used, the above process can be performed through terminating DCSF, and the appropriate data channel application can be downloaded.

[0092] After the IMS session and bootstrap data channel connection and data channel application are downloaded to UE#1 and UE#2, UE#1 can send a SIP reINVITE message containing the updated SDP to the IMS AS. The updated SDP may include not only bootstrap data channel information, but also application data channel request and related DC application binding information.

[0093] Based on user subscription data information, the IMS AS can determine whether to notify the DCSF of a media change request event. Once the IMS AS has decided to notify the DCSF of the event, it can forward the SessionEventControl_Notify message to the DCSF, containing the MediaChangeRequest Event, Session ID, Event Direction, Event Initiator, and Media Info List.

[0094] After receiving the session event notification message, the DCSF can determine the policy on how to handle the application data channel connection request based on the relevant parameters conveyed in the notification message and the network operator's policy. If UE#2 is the target endpoint and does not require an anchor of the local MF or enhanced MRF, the DCSF can decide to add the application data channel media descriptor to the SDP offer. If the MF or enhanced MRF is required as the anchor of the application data channel, the DCSF can forward the Nimsas_MediaControl message to the IMS AS to instruct the IMS AS to perform the allocation of data channel media resources of the MF or enhanced MRF.

[0095] DCSF can forward a response to the Session Event Notification message to the IMS AS. The IMS AS can then forward a SIP reINVITE message to the originating S-CSCF, which can then forward it to the terminating network and UE#2.

[0096] The 200 OK response can be included in the SDP response related to the application data channel from UE#2 and the terminating network and forwarded to the originating network. Afterwards, the IMS AS, which receives the SDP offer response message including the 200 OK response from the terminating network, can notify the DCSF of the successful data channel change. The DCSF can send a response to the notification to the IMS AS, and the IMS AS can then forward the 200 OK response to UE#1 through the originating S-CSCF and P-CSCF. At this time, the P-CSCF of the originating network can perform the QoS procedure of the application data channel media based on the SDP response information including the 200 OK response. UE#1 can send an ACK to the terminating network. Through the above process, the application data channel connection operation between UE#1 and UE#2 can be performed.

[0097] FIG. 3 is a flowchart illustrating a bootstrap data channel setup signaling procedure for requesting an IMS-DC (Internet Protocol (IP) multimedia subsystem data channel) service connection and downloading related applications in a UE according to one embodiment of the present disclosure.

[0098] In step 301, the terminal (UE#1) can transmit a SIP INVITE message including request information for a video or audio session connection to a CSCF such as a P-CSCF and an S-SCSF. In one embodiment, the SIP INVITE message can include media-related parameters such as video or audio and QoS-related requirement information in SDP and transmit them to the network using the SIP INVITE message. In addition, in order to request a service connection using additional data in addition to an existing video or audio-based session connection request, bootstrap information for an IMS data channel session connection can be transmitted together in the SDP offer. In this case, service-related specific requirement information (e.g., multiplexing support-related requirement) ('Multiplexing supported DC', 'IMS-DC-Multiplexing') can be included in the SDP attribute information and transmitted together in the bootstrap data channel-related SDP offer.

[0099] In one embodiment, the terminal may register the terminal's capability information for multiplexing by transmitting a SIP message including a multiplexing-related indicator or capability information (multiplexing support indication, or IMS-DC multiplexing capability info) to the CSCF during an IMS registration procedure in order to request and use a service through multiplexing of data streams. In one embodiment, the terminal may also include multiplexing request information in a SIP message or SDP offer without a separate registration procedure, and transmit the multiplexing-related requirement by including it in a session-level SDP attribute or a media-level attribute when requesting a call setup related to a data channel.

[0100] In one embodiment, the S-CSCF, which has received the SIP INVITE including the above SDP information, may forward the contents of the bootstrap-related SDP offer to the IMS AS if the SIP INVITE includes a bootstrap data channel SDP offer for a data channel service connection request. In one embodiment, at this time, the S-CSCF may check whether the terminal or the network supports IMS-DC based on the contents of the received bootstrap-related SDP offer, and if both sides support the data channel, may decide to forward information for a bootstrap data channel connection for the data channel connection to the IMS AS.

[0101] In one embodiment, when a multiplexing-based IMS-DC service connection request comes in as described above, the S-CSCF may determine the IMS-DC-Multiplexing Capability information of the UE based on the information in the SDP transmitted from the UE, or determine whether to support and accept the multiplexing-based IMS-DC service request based on the terminal information and the network's IMS-DC-Multiplexing Capability information received during the IMS Registration process. In one embodiment, when the terminal and the network support separate Multiplexing functions, the application list received from the terminal through the Bootstrap data channel setup process may include information on applications that support Multiplexing.

[0102] In step 302, the IMS AS, which has received the bootstrap-related SDP offer message from the S-CSCF, may first check with the HSS whether the corresponding UE or subscriber can use the data channel service supporting the multiplexing. In one embodiment, if the corresponding user cannot use the data channel supporting the multiplexing based on the user profile of the corresponding user, the application data channel connection process for each data channel stream may be performed through the general IMS-DC connection process. In another embodiment, if the corresponding user cannot use the data channel-based service supporting the multiplexing, the IMS AS may delete the multiplexing-related media information in the SIP INVITE message received from the S-CSCF, update the SIP INVITE message, and then forward the updated SIP INVITE message to the S-CSCF.

[0103] In one embodiment, if the service user can use a service based on a multiplexing-based IMS data channel, data channel bootstrapping may be performed through a data channel call request to a data channel signaling function (DCSF). In one embodiment, the IMS AS may select the DCSF by performing discovery and selection of a DCSF instance from the NRF based on a local configuration of a network operator or information transmitted from a UE. In one embodiment, the IMS AS may also determine to generate data channel service indicator information supporting multiplexing (multiplexing support indication) for the service if multiplexing-related attribute information (IMS-DC multiplexing capability info) is included in the bootstrap data channel-related SDP offer transmitted from the UE.

[0104] In step 303, the IMS AS may forward a session event control notification (SessionEventControl_Notify) message including at least one of SessionEstablishmentRequestEvent, Session ID, CallingID, CalledID, SessionCase, Event initiator, MediaInfoList, DC Stream ID, and multiplexing support indication to the DCSF selected according to the information transmitted from the UE in step 302 or the network operator policy. In one embodiment, the MediaInfoList may include IMS-DC multiplexing capability info or multiplexing support indication that supports multiplexing.

[0105] In step 304, the DCSF, which has received a DC control request for an IMS-DC service connection from the IMS AS, may perform a policy decision related to a bootstrap data channel considering multiplexing based on the relevant parameters in the DC control request message.

[0106] In steps 305 and 306, the DCSF may determine MDC1 media information to enable the UE to download applications via the MF or MRF. In one embodiment, when the DCSF receives information indicating that the UE and the network support multiplexing or multiplexing support request information in relation to the service request information of the corresponding user, the DCSF may add information on an application supporting multiplexing to the application list and provide it to the terminal. In one embodiment, if the application supporting the multiplexing is not in the DCSF, information related to an application supporting multiplexing may be requested and received from the data channel application server through steps 307 to 310.

[0107] In steps 307 and 308, the DCSF may transmit media-related information, including multiplexing support indicators received from the IMS AS, to the data channel application server via NEF. In one embodiment, the data channel application server may determine application information including a supportable replacement HTTP URL and MF-related media information (MediaInstruction) based on the received media-related information.

[0108] In steps 309 and 310, the data channel application server may transmit application information and MF-related media information (MediaInstruction) including a supportable replacement HTTP URL determined based on the information received from the DCSF in steps 307 and 308 to the DCSF via NEF.

[0109] In step 311, the DCSF may transmit a MediaControl_MediaInstruction message including information such as SessionID and MediaInstructionSet to the IMS AS based on information received from the data channel application server. In one embodiment, the DCSF may transmit to the IMS AS, in the MediaInstructionSet, replacement information such as an MDC1 media endpoint address, a DC stream ID, and a URL of an application list including application information supporting multiplexing transmitted on the MDC1 interface. In one embodiment, based on this, the DCSF may provide the IMS AS with a policy on how to create a bootstrap data channel using MF on the originating and terminating sides. In one embodiment, if the DCSF has application information supporting multiplexing and MF-related media information and can provide the related information, steps 307 to 310 may be omitted.

[0110] In step 302, the IMS AS may select an MF or an enhanced MRF based on the information received from the DCSF. The IMS AS may forward an NF Discovery Request (NFDiscovery_Request) message to the NRF for discovery and selection of an MF instance or an enhanced MRF. In one embodiment, the NRF may select an appropriate MF based on MF profile information in the NF Discovery Request message transmitted from the IMS AS for MF selection. In one embodiment, the NRF may select an MF that satisfies the MF profile requirements received from the IMS AS and forward the corresponding information to the IMS AS via an NF Discovery Request Response (NFDiscovery_Request Response) message.

[0111] In steps 303 and 314, the IMS AS may transmit a list of Media Termination Descriptors to the MF selected in the above process via an Nmf_MRM_Create message. In one embodiment, the IMS AS may request the creation of two different Media Terminations. One Media Termination may indicate local bootstrap media-related information, and the other may indicate remote bootstrap media-related information to be provided to a remote UE. In one embodiment, each Media Termination may include resource allocation request information for the Mb and MDC1 interfaces. In one embodiment, the MF may transmit the result of the negotiation of the corresponding data channel media resource information to the IMS AS.

[0112] In step 315, after receiving the data channel media resource allocation result from the MF, the IMS AS may transmit a response to the MediaInstruction request to the DCSF. In one embodiment, the response message may include information regarding the result of the operation and information regarding MDC1 data channel media resource information negotiation.

[0113] In step 316, DCSF may store media resource information in a response message for a MediaInstruction request received from the IMS AS and forward a response message related to a data channel connection notification (SessionEventControl_Notify) request from the IMS AS to the IMS AS.

[0114] At step 317, the IMS AS may send a SIP INVITE message to the S-CSCF containing an updated SDP offer with added media information and multiplexing-related indicator information of the MF or enhanced MRF.

[0115] In step 318, the S-CSCF may include the updated SDP offer, including the media information of the received MF or enhanced MRF and the multiplexing-related indicator information, in the SIP INVITE message and forward it to the remote network and UE#2.

[0116] In step 319, the negotiation process of the terminating network and UE#2 for a bootstrap data channel connection can be performed similarly to originating based on the updated SDP offer information received in step 318.

[0117] At step 320, UE#2 and the terminating network may forward an SDP response to the originating network in an 18X response message if there is a requirement for an update or change related to the bootstrap data channel. Based on the received SDP response message, the MF or enhanced MRF may update the data channel media resource information related to UE#2.

[0118] At step 321, if there are no separate changes, the terminating network and UE (UE#2) may send a 200 OK response message containing SDP answer information to the S-CSCF of the originating network.

[0119] In step 322, the S-CSCF, which has received a 200 OK response message from the terminating network and UE (UE#2), may forward the IMS data channel related SDP answer information in the 200 OK response message to the IMS AS, if any.

[0120] In step 323, the IMS AS, which has received a 200 OK message from the S-CSCF, may forward a Session Event Control Notification (SessionEventControl_Notify) message to the DCSF to inform it of event information related to a successful session connection.

[0121] In steps 324 and 325, the IMS AS, which has received a response message for the successful session connection event notification from the DCSF, may forward a 200 OK message to UE#1 containing Bootstrap related SDP answer information indicating that the Bootstrap data channel connection setup has been successfully completed.

[0122] In steps 326 (steps 326-1, 326-2, and 326-3) and 327 (steps 327-1, 327-2, and 327-3), an operation for establishing a bootstrap data channel may be performed between UE#1 and UE#2 and the originating MF or enhanced MRF. The terminal, which has received the application list including the application information supporting the multiplexing, may select an application supporting the multiplexing according to the service user's selection or the network operator's policy. In one embodiment, the UE may then transmit an application request message to the DCSF through the MF or enhanced MRF to download the corresponding application. In one embodiment, the MF or MRF may change the root URL of the application request message received from the UE to application-related URL information based on the replacement URL information received from the DCSF in step 313.

[0123] Afterwards, the MF or MRF can forward the corresponding application request message received from the UE to the DCSF via MDC1. In one embodiment, the DCSF can provide an application list or appropriate data applications to UE#1 and UE#2 based on the data channel processing capabilities and selection of the UE.

[0124] In one embodiment, if the requested data channel application is not in the DCSF, the application can be requested from the data channel application server and transmitted to UE #1 and UE #2 via MDC1 and MDC3. In one embodiment, through the above process, the terminal can download the application transmitted from the terminal via the IMS data channel and simultaneously receive application-related information such as application binding information. In one embodiment, the application-related information can include a Bootstrap DC stream ID, which indicates through which Bootstrap channel the application was transmitted.

[0125] In one embodiment, the Bootstrap DC stream ID or Bootstrap DC ID can be used to determine which data channel server among local or remote data channel servers (e.g., DCSF) the terminal received the application from, and the information can be included in the subsequent application data channel setup signaling process to provide information for connecting to an appropriate data channel server.

[0126] In steps 328 (steps 328-1, 328-2, and 328-3) and 329, an IMS data channel service can be used by connecting a bootstrap data channel using an MF or MRF on the terminating network, depending on the location of the MF or MRF. A terminal that has received an application list including application information supporting the above multiplexing can select an application supporting multiplexing according to a service user's choice or a network operator's policy. In one embodiment, each UE can then transmit an application request message to the terminating DCSF through the MF or enhanced MRF on the terminating network to download the corresponding application.

[0127] In one embodiment, the terminating DCSF may provide an application list or appropriate data applications to UE#1 and UE#2 based on the data channel processing capability and selection of the UE. In one embodiment, if the requested data channel application is not in the DCSF, the application may be requested from the data channel application server and transmitted to UE#1 and UE#2 via MDC1 and MDC3. In one embodiment, the application-related information may include a Bootstrap DC stream ID, which indicates through which Bootstrap channel the application was transmitted.

[0128] In one embodiment, the Bootstrap DC stream ID or Bootstrap DC ID may be used to determine which data channel server (e.g., DCSF) the terminal received the application from, among local or remote data channel servers, and may then include the information in the application data channel setup signaling process to provide information for connecting to the appropriate data channel server. In step 330, subsequent procedures after step 329 may be performed.

[0129] FIG. 4 is a flowchart illustrating the operation of a P-CSCF for supporting a multiplexing-based application data channel service when requesting it during an application data channel setup signaling procedure in a UE according to one embodiment of the present disclosure.

[0130] In step 401, the terminal (UE#1) may transmit a SIP re-INVITE message to the P-CSCF for an application data channel connection. In one embodiment, for the application data channel connection, the terminal may transmit an SDP offer including application-related binding information such as an application-related stream ID and application ID received through the bootstrap data channel connection process and additionally bootstrap DC stream ID information to the network through the SIP re-INVITE message to perform a data channel session connection request operation. In one embodiment, the SDP offer for an application data channel connection that supports multiplexing may include information that the terminal receives data streams of multiple applications through a single port (multiplexing support indication). In this case, one application may be composed of one or more data streams. In addition, one SDP offer may include information on data streams transmitted to different endpoints or on data streams transmitted to the same endpoint. At this time, different endpoints may represent different application connection types (e.g., P2A and P2P) or MF locations (local and remote MF). In one embodiment, information for connecting MFs with different endpoints can be distinguished using the bootstrap stream ID in the binding information or identification information for each application.

[0131] In step 402, the P-CSCF, which receives a SIP re-INVITE containing an SDP offer indicating that multiple applications are to be delivered to the single port, may determine an action to support the multiplexing function. In one embodiment, the P-CSCF may configure an IMS-AGW via an IMS-ALG (Application Level Gateway) within the P-CSCF to support the multiplexing function, and may request relevant information from the IMS-AGW.

[0132] In step 403, the P-CSCF may request the IMS-AGW, through the IMS-ALG, to allocate as many ports as the number of data streams corresponding to the single data stream and to transmit the corresponding information in order to support the multiplexing and de-multiplexing functions of the data streams transmitted from the terminal as a single data stream. In one embodiment, the P-CSCF may request the IMS-AGW for multiplexing, i.e., transmission of the IMS-DC and related information, and the request may include a multiplexing support indication. The IMS-AGW may allocate data stream-related information based on the data stream information of the applications in the single m line in the SDP offer and then transmit the same to the P-CSCF.

[0133] In step 404, the P-CSCF may classify the information of the SDP offer in the SIP re-INVITE received from UE#1 according to the connection type of the application. In one embodiment, the P-CSCF may also update the SDP offer based on the allocated information (e.g., IP address, port, etc.) for each data stream received from the IMS-AGW. For example, a message including a connection request to a remote UE and a connection request to an application server may be received in the SDP offer according to the application connection type. At this time, in one embodiment, the P-CSCF may update the SDP offer information of the application DC by separating the m lines for the remote UE and the application connection according to the connection type of the application in the corresponding SDP offer to support multiplexing. Alternatively, when using different remote endpoints, the P-CSCF may separate the m lines in the SDP offer for each endpoint to update the SDP offer information of the application DC.

[0134] In step 405, a modified SDP offer message based on IMS-AGW allocation information, etc., may be transmitted to the IMS AS through the S-CSCF to support multiplexing from the P-CSCF. In one embodiment, the modified SDP offer message may be updated based on the application connection type. In one embodiment, the S-CSCF, which has received SIP re-INVITE information including updated SDP offer information to support multiplexing from the P-CSCF, may determine whether to accept multiplexing of data streams using the multiplexing application of the corresponding terminal based on subscription information of the corresponding service user and whether the network supports multiplexing. In one embodiment, if the multiplexing support request of the corresponding service user is accepted, an application data channel connection request message including the updated SDP offer may be transmitted to the IMS-AS. In one embodiment, the IMS-AS may first confirm with the HSS whether the corresponding UE or subscriber can use a data channel service through the multiplexing-based application data channel connection, and then determine whether to accept the application data channel connection request.

[0135] FIG. 5 is a flowchart for explaining an application data channel setup signaling process according to the connection type of the application data channel in an IMS AS (IP (internet protocol) multimedia subsystem application server) according to one embodiment of the present disclosure.

[0136] FIG. 5 is a flowchart illustrating a method for transmitting information for updating DCSF policies and updating related media resources within MF entities to perform a connection operation of an application data channel considering a P2P (Person to Person) connection type according to one embodiment of the present disclosure.

[0137] In step 501, the IMS AS may receive an updated SDP offer message through the S-CSCF based on IMS-AGW allocation information, etc. to support multiplexing from the P-CSCF. In one embodiment, the IMS-AS may request the DCSF for an application data channel connection based on the application data channel connection request message including the updated SDP offer information and bootstrap stream ID for supporting multiplexing received from the S-CSCF. In one embodiment, when the IMS-AS performs an application data channel connection through the local DCSF based on the bootstrap stream ID, the local IMS-AS may determine to generate a session event control notification (SessionEvent_Control_Notify) message. In one embodiment, when the IMS-AS performs an application data channel connection through the remote DCSF based on the bootstrap stream ID, the IMS-AS may retransmit the updated SDP offer information received from the S-CSCF through the S-CSCF and request that it be transmitted in the remote network. In one embodiment, an S-CSCF within a remote network that has received the updated SDP offer may request to perform an application data channel connection.

[0138] In one embodiment, the IMS-AS may perform a media data channel connection operation for transmitting and receiving application data through a session connection request for application data channel setup using the Data Channel Signaling Function (DCSF) when the service user can use an IMS data channel-based service. In one embodiment, the IMS AS may select a DCSF (e.g., a local DCSF or a remote DCSF) based on a Bootstrap DC ID received during the bootstrap data channel connection process. In this embodiment, it is assumed that the application data channel connection operation is performed using a local DCSF and an MF.

[0139] In step 502, IMS-AS may transmit a SessionEventControl_Notify message containing information such as MediaChangeRequest Event, Session ID, Event Direction, Event initiator, and Media Info List for requesting application data channel connection to DCSF. In one embodiment, the Media Info List may include IMS-AGW-related information (modified SDP info) of the corresponding application-related data stream updated and transmitted through P-CSCF.

[0140] In step 503, the DCSF, which has received a message including the media change request event, can perform a data channel control policy update for multiplexing support and application data channel connection.

[0141] In step 504, the DCSF may determine to transmit relevant information for an e2e application data channel connection to the remote network and UE based on media-related information received from the IMS AS, if the connection type of the application data channel is a P2P connection type. In one embodiment, the DSCF may allow the DC e2e application stream to be exposed to the remote party.

[0142] In step 505, depending on whether MF anchoring is required, a decision may be made as to whether to update or add data channel media resources within the MF entity for connecting a new application data channel requested from the terminal. In one embodiment, even when the application connection type is P2P, anchoring through a separate MF may be required in DCSF due to protocol changes, etc., when connecting a new application data channel.

[0143] At this time, in step 506, the DCSF can update and forward the data channel media resources of the MF entity (e.g., Port information for anchoring media streams, etc.) and the SDP offer to be delivered to the remote network and UE to the IMS AS. In one embodiment, if there is no need for connection between UEs through anchoring of a separate MF, the DCSF can update the data channel policy information based on the application data channel information and forward it to the IMS-AS.

[0144] In step 507, the IMS-AS, which has received the updated data channel media resources and the updated SDP offer info delivered to the remote network and UE, can deliver them to the MF to perform a media resource allocation operation for a P2P connection operation through MF anchoring.

[0145] At step 508, the MF or MRF may forward anchoring related information (e.g. Port info etc.) of the application data channel in that MF or MRF for connection via MF or MRF anchoring to the IMS AS.

[0146] In step 509, the IMS AS may forward a Nimsas_MediaControl_MediaInstruction response message to the DCSF, which includes the success or failure of the media resource update of the MF or MRF entity for the application data channel connection using MF or MRF anchoring and the relevant information allocated for anchoring of the corresponding application data channel in the MF or MRF.

[0147] In step 510, the DCSF can update the SDP offer information to be transmitted to the remote network and UE and forward it to the IMS AS. If the application data channel connection is performed using MF or MRF anchoring, the DCSF can update the SDP offer based on the endpoint information of each MF or MRF and forward it to the IMS AS. If it is decided to perform an e2e application data channel connection without separate MF or MRF anchoring in step 505, steps 506 to 509 can be omitted.

[0148] When using a data channel service based on multiplexing using IMS-AGW as in an embodiment of the present invention, in order to connect an application data channel without using separate MF or MRF anchoring, the IMS AS can transmit a SIP re-INVITE message including endpoint information in an SDP offer generated based on endpoint information of the IMS-AGW received from the P-CSCF to a remote network.

[0149] FIG. 6 is a flowchart for explaining an application data channel setup signaling process according to the connection type of the application data channel in an IMS AS (IP (internet protocol) multimedia subsystem application server) according to one embodiment of the present disclosure.

[0150] FIG. 6 is a flowchart illustrating a method for transmitting information for updating DCSF policies and updating related media resources within an MF entity to perform a connection operation of an application data channel considering a P2A (Person to Application) connection type according to one embodiment of the present disclosure.

[0151] In step 601, the IMS AS may receive an updated SDP offer message through the S-CSCF based on IMS-AGW allocation information, etc. to support multiplexing from the P-CSCF. The IMS-AS may request the DCSF for an application data channel connection based on the application data channel connection request message including the updated SDP offer information and bootstrap stream ID for supporting multiplexing received from the S-CSCF. In this case, in one embodiment, when the IMS AS performs an application data channel connection through the local DCSF based on the bootstrap stream ID, the local IMS-AS may determine to generate a session event control notification (SessionEvent_Control_Notify) message. In one embodiment, when the IMS-AS performs an application data channel connection through the remote DCSF based on the bootstrap stream ID, the IMS-AS may retransmit the updated SDP offer information received from the S-CSCF through the S-CSCF and request that it be transmitted in the remote network. In one embodiment, an S-CSCF within a remote network that has received the updated SDP offer may request to perform an application data channel connection.

[0152] When a service user can use an IMS data channel-based service, the IMS AS can perform a media data channel connection operation for transmitting and receiving application data through a session connection request for application data channel setup using the data channel signaling function (DCSF). The IMS AS can select a DCSF (e.g., local DCSF or remote DCSF) based on the bootstrap DC ID received during the bootstrap data channel connection process. In this embodiment, it is assumed that the application data channel connection operation is performed using the local DCSF and MF.

[0153] In step 602, IMS-AS may transmit a SessionEventControl_Notify message containing information such as MediaChangeRequest Event, Session ID, Event Direction, Event initiator, and Media Info List for requesting application data channel connection to DCSF. The Media Info List may include IMS-AGW-related information of the corresponding application-related data stream updated and transmitted through P-CSCF.

[0154] In step 603, the DCSF, which has received information including the media change request event, can perform a data channel control policy update for application data channel connection considering multiplexing based on the relevant parameters in the session event control notification message.

[0155] In step 604, the DCSF may generate related information for data channel application server connection if the connection type of the application data channel is a P2A connection type based on the media-related information received from the IMS AS. In one embodiment, the DCSF may determine, based on the related information related to the application data channel, to generate data channel media resource information including information (MDC2 Endpoint) for media data channel connection and update the data channel control policy if the connection type of the application data channel is an application data channel using a data channel application server.

[0156] In step 605, the DCSF may include information related to the MF and the data channel application server for application data channel connection in the data channel media resource information and transmit the information to the IMS AS through media-related instruction (MediaInstruction) for media control. In one embodiment, the media resource information may include information for updating or adding data channel media resources in the MF entity. In one embodiment, the media resource information transmitted from the DCSF may include SDP offer information updated in the P-CSCF to support multiplexing. In one embodiment, the IMS AS may transmit packets in the data channel on the user plane from each UE to the MF or enMRF, and the MF or enMRF may receive media resource information including media instruction information for transmitting the packets to the data channel application server using the MDC2 interface from the DCSF. In one embodiment, the IMS AS may transmit a request for allocation of the corresponding media resource information and MDC2 media information to the MF. Using the MDC2 media information request, the MF can allocate data channel media resources to transmit application data transmitted from the UE to the data channel application server.

[0157] In step 606, the IMS AS, which has received the data channel media resource including the MDC2 media information and the updated SDP information, can forward the media resource information for the application data channel connection considering the P2A connection type to the MF or enMRF via a media resource management request (Nmf_MRM_Create Request) message. If the UE's application data is to be forwarded to the data channel application server using the MRF, the UE can request the MRF to allocate the relevant data channel media resources via the Mr' / Cr interface.

[0158] In step 607, the MF may forward the MDC2 media information and media resource allocation result information of the MF to the IMS AS via a media resource management request response (Nmf_MRM_Create Request Response) message, taking into account the P2A connection type.

[0159] At step 608, the IMS AS may forward the media resource information of the MF entity for the P2A connection, including the MDC2 media information received from the MF or enMRF, to the DCSF.

[0160] In steps 609 and 610, the DCSF may store media resource information and then forward a P2A application data channel establishment request to the data channel application server (DC-AS) via DC3 or DC4. In one embodiment, if the data channel application server accepts the application data channel establishment request forwarded through the above process, it may forward MDC2-related SDP response information (MDC2 media endpoint information) to the DCSF.

[0161] In step 611, the DCSF may perform a data channel media resource update based on the MDC2 media endpoint information of the data channel application server received from the data channel application server, and then transmit the updated data channel media resource information to the IMS AS based on the MDC2-related SDP response information (MDC2 media endpoint information).

[0162] In steps 612 and 613, the IMS AS may request a resource update of the media function entity based on the updated data channel media resource information and receive the update result value from the MF.

[0163] In step 614, the IMS AS may notify the DCSF of the response information for the media control related instruction including the result of the successful data channel related media resource update after receiving the update result value from the MF.

[0164] In step 615, the DCSF may transmit a response message including an updated SDP answer based on MDC2-related information for application data channel connection considering P2A connection after being notified of response information for media control-related instructions to the IMS AS. In one embodiment, when an application data channel connection based on a P2A connection type is established, the IMS AS, which has received a data channel-related response message from the DCSF, may wait for a response message transmitted from the remote network and may add the response message to a 200 OK response message and transmit it to UE #1. In addition, the IMS AS may delete application data channel-related SDP offer information when transmitting a SIP re-INVITE to the remote network and transmit only video or audio-related SDP offers.

[0165] In one embodiment, through the above process, the IMS AS can perform operations for updating application data channel related information considering the P2A connection type and allocating media resources within the MF entity, and based on the result, can forward a SIP re-INVITE message including the updated SDP offer to the remote network through the S-CSCF.

[0166] FIG. 7 is a flowchart for explaining an application data channel setup signaling process according to the connection type of the application data channel in an IMS AS (IP (internet protocol) multimedia subsystem application server) according to one embodiment of the present disclosure.

[0167] FIG. 7 is a flowchart illustrating a method for transmitting information for updating DCSF policies and updating related media resources within an MF entity to perform a connection operation of an application data channel considering a P2A2P (Person to Application to Person) connection type according to one embodiment of the present disclosure.

[0168] In step 701, the IMS AS may receive an updated SDP offer message through the S-CSCF based on IMS-AGW allocation information, etc. to support multiplexing from the P-CSCF. In one embodiment, the IMS-AS may request the DCSF for an application data channel connection based on the application data channel connection request message including the updated SDP offer information and bootstrap stream ID for supporting multiplexing received from the S-CSCF. In one embodiment, the IMS-AS may determine to generate a SessionEvent_Control_Notify message in the local IMS-AS when performing an application data channel connection through the local DCSF based on the bootstrap stream ID. In one embodiment, when performing an application data channel connection through a remote DCSF based on the bootstrap stream ID, the IMS-AS may retransmit the updated SDP offer information received from the S-CSCF through the S-CSCF and request that the same be transmitted in the remote network. In one embodiment, an S-CSCF within a remote network that has received the updated SDP offer may request to perform an application data channel connection.

[0169] In one embodiment, the IMS-AS may perform a media data channel connection operation for transmitting and receiving application data through a session connection request for application data channel setup using the Data Channel Signaling Function (DCSF) when the service user can use an IMS data channel-based service. In one embodiment, the IMS AS may select a DCSF (e.g., a local DCSF or a remote DCSF) based on a Bootstrap DC ID received during the bootstrap data channel connection process. In this embodiment, it is assumed that the application data channel connection operation is performed using a local DCSF and an MF.

[0170] In step 702, IMS-AS may transmit a SessionEventControl_Notify message containing information such as MediaChangeRequest Event, Session ID, Event Direction, Event initiator, and Media Info List for requesting application data channel connection to DCSF. In one embodiment, the Media Info List may include IMS-AGW-related information of the corresponding application-related data stream updated and transmitted via P-CSCF.

[0171] In step 703, the DCSF, which has received information including the media change request event, can perform a data channel control policy update for application data channel connection considering multiplexing.

[0172] In step 704, the DCSF may generate related information for data channel application server connection if the connection type of the application data channel is a P2A2P connection type based on the media-related information received from the IMS AS. In one embodiment, the DCSF may determine, based on the related information related to the application data channel, to generate data channel media resource information of an MF entity including information for media data channel connection for each UE (MDC2 Endpoint per UE) and update a data channel control policy if the connection type of the application data channel is an application data channel using a data channel application server.

[0173] In step 705, the DCSF may include information related to the MF and the data channel application server for application data channel connection in the data channel media resource information and transmit the information to the IMS-AS through media-related instruction (MediaInstruction) information for media control. In one embodiment, the media resource information may include information for updating or adding data channel media resources in the MF entity. In one embodiment, the media resource information transmitted from the DCSF may also include SDP offer information updated in the P-CSCF to support multiplexing. In one embodiment, the IMS AS may transmit packets in the user plane data channel from each UE to the MF or enMRF, and the MF or enMRF may receive media resource information including media instruction information for transmitting the packets to the data channel application server using the MDC2 interface from the DCSF. In one embodiment, the IMS AS may transmit a request for allocation of the corresponding media resource information and MDC2 media information to the MF. In one embodiment, the MF may use the MDC2 media information request to allocate data channel media resources for transmitting application data transmitted from the UE to the data channel application server. Unlike the embodiment for application data channel connection based on the P2A connection type of FIG. 6, for application data channel connection based on the P2A2P connection type of FIG. 7, the MF may generate and allocate MDC2 media information for each UE.

[0174] In step 706, the IMS AS, which has received the data channel media resource including the MDC2 media information and the updated SDP information from the DCSF, may forward the media resource information for the application data channel connection considering the P2A2P connection type to the MF or enMRF via a media resource management request (Nmf_MRM_Create Request) message. If the UE's application data is to be forwarded to the data channel application server using the MRF, the UE may request the MRF to allocate the relevant data channel media resource via the Mr' / Cr interface.

[0175] In step 707, the MF (or enMRF) may forward the MDC2 media information and media resource allocation result information for each UE of the MF to the IMS AS via a media resource management request response (Nmf_MRM_Create Request Response) message, taking into account the P2A2P connection type.

[0176] At step 708, the IMS AS may forward the media resource information of the MF entity for the P2A2P connection, including the MDC2 media information received from the MF or enMRF, to the DCSF.

[0177] In step 709, DCSF may store media resource information and then transmit a P2A2P application data channel establishment request to the data channel application server via DC3 or DC4. In step 710, if the data channel application server (DC-AS) accepts the application data channel establishment request transmitted through the above process, it may transmit MDC2-related SDP response information (MDC2 media endpoint information) for each UE to DCSF.

[0178] In step 711, the DCSF may perform a data channel media resource update based on the UE-specific MDC2 media endpoint information of the data channel application server received from the data channel application server, and then transmit the updated data channel media resource information to the IMS AS based on the MDC2-related SDP response information (MDC2 media endpoint information).

[0179] In steps 712 and 713, the IMS AS may request a resource update of the media function entity based on the updated data channel media resource information and receive the update result value from the MF.

[0180] In step 714, the IMS AS may notify the DCSF of the response information for the media control related instruction including the result of the successful data channel related media resource update after receiving the update result value from the MF.

[0181] In step 715, after receiving the response information for the media control related instruction, the DCSF may forward a response message to the IMS AS including an SDP offer for connection of an updated application data channel based on the MDC2 related information for connection of an application data channel considering the P2A2P connection.

[0182] Through the above process, the IMS AS can perform actions for updating application data channel related information considering the P2A2P connection type and allocating media resources within the MF entity, and based on the result, can forward a SIP re-INVITE message including the updated SDP offer to the remote network through the S-CSCF.

[0183] FIG. 8 is a flowchart illustrating an application data channel setup signaling process for transmitting related information for application data channel connection to a remote network in an IMS AS (IP (internet protocol) multimedia subsystem application server) according to one embodiment of the present disclosure and receiving a requested result from the remote network.

[0184] Prior to steps 801 and 802, the IMS AS may receive data channel resource allocation and related information according to the connection type of the application data channel from the DCSF, as shown in FIGS. 5, 6, and 7. In steps 801 and 802, the IMS AS may forward a SIP re-INVITE message containing updated SDP offer information based on the information received from the DCSF to the remote network. In one embodiment, when performing an application data channel connection using MF or MRF anchoring in a P2P connection type, the SDP offer may be updated based on the endpoint information of each MF or MRF. In one embodiment, for an application data channel connection that does not go through separate MF or MRF anchoring in a P2P connection type, the IMS AS may forward a SIP re-INVITE message containing endpoint information in an SDP offer generated based on the endpoint information of the IMS-AGW received from the P-CSCF to the remote network. In one embodiment, if the connection type is P2A, the re-INVITE message may not include an SDP offer related to the application data channel.

[0185] In step 803, the terminating network and UE#2 may perform a negotiation process for an application data channel connection based on the SIP re-INVITE information including the updated SDP offer information received in step 802. In one embodiment, a multiplexing-based application data channel connection may be determined depending on whether the remote UE (UE#2) and the remote network support it. In one embodiment, if the remote UE and the network support a multiplexing-based application data channel, the remote UE and the network may select an application that supports multiplexing and then perform an application data channel connection using the application. In one embodiment, if at least one of the remote UE or the network does not support multiplexing, the remote UE may select a general application that does not support multiplexing from the application list received during the bootstrap data channel connection process.

[0186] In steps 804 and 805, if the remote UE (UE#2) and the network support multiplexing, updated SDP answer information including data stream related information of the IMS-AGW in the remote network may be forwarded to the Originating network via a 200 OK response message. In one embodiment, the S-CSCF may forward information in the 200 OK response message forwarded from the remote network and the UE to the IMS AS. In one embodiment, if at least one entity among the remote UE or the network does not support multiplexing, SDP answer information including data stream related information of the remote UE may be forwarded to the Originating network via a 200 OK response message.

[0187] In one embodiment, in response to an application data channel connection request using a P2A connection type, audio and video related SDP responses may be included in a 200 OK response message and forwarded to the IMS AS via the S-CSCF. In one embodiment, the S-CSCF may forward the 200 OK response message to the IMS AS, and the IMS AS, upon receiving the message, may notify the DCSF of the result of a successful media change request event.

[0188] Based on the SDP Answer information received from the remote network and UE at step 806, the IMS AS can notify the DCSF that the application data channel connection has been successfully completed.

[0189] In step 807, the DCSF, which received the session event control notification message in step 806, may forward a response to the notification message to the IMS AS.

[0190] In steps 808 and 809, the IMS AS may forward a 200 OK message including SDP Answer information received from the remote network and the UE to the P-CSCF via the S-CSCF. In one embodiment, for an application data channel using a P2A connection type, the IMS AS may add a response message (SDP answer for P2A connection between UE#1 and DC-AS) for connection request information between UE#1 and a data channel application server to the 200 OK response message including audio and video related SDP responses received from the remote network and UE#2, and forward it to the S-CSCF and the P-CSCF.

[0191] In step 810, the P-CSCF may forward application data channel information in the SDP Answer for QoS allocation to the PCF based on the information in the 200 OK message so that an appropriate QoS can be allocated.

[0192] In step 811, the P-CSCF, which has received QoS information based on the application data channel information, can finally transmit 200 OK information to the UE.

[0193] At step 812, UE#1 can finally transmit to the remote network and UE#2 via an ACK message that successful application data channel establishment has been completed based on information from the remote network and the UE.

[0194] Step 813a represents an application data channel connection considering a P2P connection type, and connects an application data channel through a P2P connection between UE#1 and UE#2, through which UE#1 and UE#2 can transmit and receive data. In one embodiment, if UE#1 and UE#2 are using a P2P connection through MF anchoring, the application data information received from UE#2 (e.g., port information of UE#2, etc.) may be transmitted from the IMS AS to the MF through a data channel media resource update process, and based on the result value, the DCSF may be notified that a successful application data channel connection has been established. After this, the IMS-AS may transmit 200 OK information to the P-CSCF through the S-CSCF based on the response message of the DCSF, and based on the information in the 200 OK, the application data channel information may be used to perform appropriate QoS allocation, and finally complete the application data channel connection through the P2P connection through MF anchoring.

[0195] Step 813b represents an application data channel connection considering the P2A connection type, where UE #1 can use an IMS data channel related service by using an application data channel using a data channel application server and MDC2 while using an audio or video related IMS call session with UE #2.

[0196] Step 813c represents an application data channel connection considering the P2A2P connection type, and UE #1 and UE #2 can transmit and receive application data through the data channel application server via MF or enMRF.

[0197] FIG. 9 is an example of SDP offer and SDP answer information transmitted from a session request and response message that supports multiplexing for an application data channel connection request in a terminal according to an embodiment of the present invention.

[0198] Figure 9 (a) is an example of SDP offer information transmitted from UE#1 to P-CSCF. One m-line is included in one SDP offer, and the configuration information of the corresponding application includes IP information of UE#1 and information of DTLS (datagram transport layer security) / SCTP (stream control transmission protocol) #1. In addition, it can be seen that the connection type of the application data channel requested through the SDP offer includes connection types of P2A (app-binding: 2000) and P2P (app-binding: 2001). Based on the above information, it can be seen that data streams of multiple applications are requested through one DTLS connection.

[0199] In (b) of Fig. 9, the P-CSCF, which has received the SIP re-INVITE message including the SDP offer of (a) of Fig. 9, can recognize that the connection request is a multiplexing-based application data channel connection request. In one embodiment, the P-CSCF can perform transmission and request of IMS-AGW-related information through IMS-ALG (application level gateway). Based on the request, the P-CSCF can determine the generation and transmission of indicator information requesting multiplexing support to IMS-AGW and multiplexing-related information of the application data channel. In one embodiment, the P-CSCF can request as many DTLS / SCTP connections as the number of data streams constituting each application. In (b) of Fig. 9, it is assumed that each application has one data stream and that there is one application for each connection type of the application data channel. In other words, it can indicate a request in which there is one data stream for each application data channel type. The IMS-AGW that receives the information can determine two DTLS / SCTP connections and forward the data stream related information (e.g. c=IPofIMSAGW) to the P-CSCF to generate an updated SDP offer in the P-CSCF, or the IMS-AGW can forward the updated SDP offer information to the P-CSCF.

[0200] In the embodiment of the present disclosure, based on one m-line, for each application data channel connection type, m-line#2 is used for P2A, and m-line#3 is used for P2P, and the SDP offer is updated with data stream related information received from the IMS-AGW, and the SDP offer is transmitted to the IMS AS.

[0201] In (c) of FIG. 9, if the application data channel connection type requires a data channel application server connection, such as P2A, the IMS AS can receive related information from the MF or enMRF and DCSF and perform an SDP offer update based on the information. Multiple application data channel connection types can be requested to be connected together in one multiplexed data stream, and separate information reception and update processes can be performed for each application data channel connection type. In the embodiment of the present disclosure, in the case of a P2P scenario, an application data traffic transmission scenario through an e2e application data channel connection between terminals can be assumed, where the MF or enMRF anchoring scenario is not considered. In one embodiment, when an application data channel connection based on a P2P connection type through an e2e application data channel connection between terminals is established, the IMS AS can transmit the changed SDP offer information (m-line #3) to the remote network without a separate update based on the IMS AWG-based data stream information received from the P-CSCF. In one embodiment, when an application data connection request is made based on a P2A2P connection type, the IMS AS updates the SDP offer by reflecting updated media resource information considering the connection between the MF and UE#2 in the corresponding m-line information (m-line #2), and updates or replaces the SIP re-INVITE message with the updated SDP offer (m-line #4) and forwards it to the remote network.

[0202] Figure 9 (d) is an example of SDP answer information transmitted to the IMS AS based on information transmitted from the remote network. The remote UE's response information, including the IP information of UE#2 and DTLS / SCTP-related information for application data channel connection based on P2P connection between UEs, can be included in m-line #3 and transmitted to the IMS AS through the S-CSCF. In one embodiment, the remote UE's response information, including the IP information of UE#2 and DTLS / SCTP-related information for application data channel connection based on P2A2P connection, can be included in m-line #4 and transmitted to the IMS AS through the S-CSCF.

[0203] FIG. 9 (e) is an example of SDP answer information that the IMS AS transmits to the DCSF based on the information transmitted from the remote network, indicating successful completion of the application data channel connection and information related to the remote network and UE (UE #2). Based on this information, the DCSF can update media resource information within the MF. Thereafter, the IMS AS can change or update the SDP offer information based on the 200 OK response message received from the remote UE and the network and transmit a 200 OK response message to UE #1. As shown in FIG. 9 (e), in the case of a P2P connection type, a separate SDP answer information update is not performed, but in the case of an application data channel connection using a connection to a data channel application server, the SDP offer information transmitted from the remote network can be updated with the corresponding MF-related information and transmitted. In addition, in order to utilize the DTLS / SCTP connection between the IMS-AGW and the MF, the relevant information can be updated in the IMS AS or DCSF and transmitted as an SDP answer within the 200 OK response message transmitted to UE #1. A P-CSCF that receives a 200 OK response message including an SDP answer such as the example in (e) of Fig. 9 can complete an application data channel connection operation considering multiplexing by transferring the corresponding SDP answer information to the IMS AGW.

[0204] As shown in (f) of Fig. 9, after completing the application data channel connection operation considering QoS allocation and multiplexing, the P-CSCF may decide to update or change the SDP answer information including IMS-AGW related information (c=IPofIMSAGW) transmitted to UE #1.

[0205] FIG. 10 is a structural diagram illustrating the structure of a network entity according to one embodiment of the present disclosure.

[0206] The network entities illustrated in FIG. 10 may include network entities mentioned in the present disclosure, such as P-CSCF, IMS AS, IMS-AGW, S-CSCF, etc.

[0207] A network entity according to one embodiment of the present disclosure may include a processor (1020) that controls the overall operation of the network entity, a transceiver (1000) including a transmitter and a receiver, and a memory (1010). Of course, the present invention is not limited to the above example, and the network node may include more or fewer components than those illustrated in FIG. 10.

[0208] According to one embodiment of the present disclosure, the transceiver (1000) can transmit and receive signals with network entities or other network nodes. The signals transmitted and received with the network entities may include control information and data. In addition, the transceiver (1000) can receive signals via a wireless channel, output them to the processor (1020), and transmit the signals output from the processor (1020) via the wireless channel.

[0209] According to one embodiment of the present disclosure, the processor (1020) can control receiving a data channel session connection request message including session description protocol (SDP) offer information from a user equipment (UE). In one embodiment, the SDP offer information can include multiplexing-related information. In one embodiment, the processor (1020) can control transmitting a request for data stream-related information including the SDP offer information to an IMS-AGW (application gateway) entity, receiving the data stream-related information for multiplexing support based on the SDP offer information from the IMS-AGW entity, and updating the SDP offer information based on the data stream-related information for multiplexing support.

[0210] According to one embodiment of the present disclosure, the multiplexing-related information may be received by a terminal through a single port for data streams of multiple applications. In one embodiment, the processor (1020) may update the SDP offer information based on the connection type information of the application included in the SDP offer to support the multiplexing.

[0211] In one embodiment, the processor (1020) may control the transmission of the updated SDP offer to an IMS application server (AS). In one embodiment, the updated SDP offer information may be used to update a data channel control policy.

[0212] According to one embodiment of the present disclosure, the processor (1020) may receive a request for data stream related information including multiplexing related information from a proxy-call state control function (P-CSCF) entity, and control the P-CSCF to transmit the data stream related information based on the multiplexing related information. In one embodiment, the data stream related information may be used to update SDP offer information received from a user equipment (UE). In one embodiment, the SDP offer information may include the multiplexing related information.

[0213] According to one embodiment of the present disclosure, a method of an IMS AS (Internet Protocol (IP) multimedia subsystem application server) entity in a wireless communication system includes the steps of: transmitting request information for multiplexing based on request information of a service; transmitting a request message for discovering a media function (MF) entity including the request information for multiplexing to a network repository function (NRF) entity; and receiving a response message including information related to an MF entity selected based on the request information for multiplexing from the NRF entity; wherein the request information of the service includes request information for multiplexing received from a terminal.

[0214] According to one embodiment of the present disclosure, a method of a Proxy Call State Control Function repository function (P-CSCF) entity in a wireless communication system comprises the steps of: receiving a call session connection request message using SDP offer information including request information for multiplexing from a UE; And a step of transmitting an SDP offer including request information for multiplexing of data streams by application type (e.g., P2P (Person to Person), P2A (Person to Application), P2A2P (Person to Application to Person, etc.)) based on the multiplexing request information to the IMS AS entity; wherein the multiplexing request information may include connection information between a media function entity and a remote UE (e.g., UE #2) when the application type is P2A or P2A2P, and based on the request information for multiplexing, the SIP INVITE message transmitted from the IMS-AS to the terminating network / UE may include modified SDP offer information, and may receive mapping information between the remote UE and the MF and the IMS-AGW in a 200 OK message including an SDP response message transmitted from the remote UE based on the transmitted information.

[0215] According to one embodiment of the present disclosure, in a wireless communication system, an IMS AS (Internet Protocol (IP) multimedia subsystem application server) entity comprises: a transceiver; and at least one processor; wherein the at least one processor is configured to receive an SDP offer including request information for multiplexing from a UE based on request information for a service, transmit a request message for discovering an application supporting multiplexing based on the request information to a DCSF (Data Channel Signaling Function), and receive a response message including an application list with information related to an application selected based on the request information for supporting the multiplexing from the DCSF entity, wherein the request information for the service includes request information for supporting multiplexing received from a terminal.

[0216] According to one embodiment of the present disclosure, in a wireless communication system, a Proxy Call State Control Function repository function (P-CSCF) entity includes a transceiver; and at least one processor, wherein the at least one processor is configured to receive a call session connection request message including request information for supporting multiplexing from a UE, and transmit mapping information for supporting multiplexing within the IMS-AGW through signaling between an IMS-AGW and an IMS-ALG within the P-CSCF for supporting multiplexing, and transmit a SIP Invite message including SDP offer information changed based on the request information for supporting multiplexing to an IMS AS entity to a remote network or the UE, and based on the information in an SDP response message received by the remote UE, receive mapping information for supporting multiplexing from the IMS-AS and transmit and update the same to the IMS-AGW.

[0217] The methods according to the embodiments described in the claims or specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

[0218] When implemented in software, a computer-readable storage medium storing one or more programs (software modules) may be provided. The one or more programs stored in the computer-readable storage medium are configured for execution by one or more processors within an electronic device. The one or more programs include instructions that cause the electronic device to execute methods according to embodiments described in the claims or specification of the present disclosure.

[0219] These programs (software modules, software) may be stored in a non-volatile memory including random access memory, flash memory, read only memory (ROM), electrically erasable programmable read only memory (EEPROM), magnetic disc storage devices, compact disc ROMs (CD-ROMs), digital versatile discs (DVDs) or other forms of optical storage devices, magnetic cassettes, or may be stored in a memory configured as a combination of some or all of these. In addition, each configuration memory may be included in multiple numbers.

[0220] Additionally, the program may be stored on an attachable storage device that is accessible via a communication network such as the Internet, an intranet, a local area network (LAN), a wide local area network (WLAN), a storage area network (SAN), or a combination thereof. Such a storage device may be connected to a device implementing an embodiment of the present disclosure via an external port. Additionally, a separate storage device on the communication network may be connected to a device implementing an embodiment of the present disclosure.

[0221] In the specific embodiments of the present disclosure described above, components included in the present disclosure are expressed singularly or plurally, depending on the specific embodiment presented. However, the singular or plural expressions are selected to suit the presented situation for convenience of explanation, and the present disclosure is not limited to singular or plural components. Components expressed in plural may be composed of singular elements, or components expressed in singular may be composed of plural elements.

[0222] While the detailed description of this disclosure has described specific embodiments, it should be understood that various modifications are possible without departing from the scope of this disclosure. Therefore, the scope of this disclosure should not be limited to the described embodiments, but should be defined not only by the scope of the claims described below, but also by equivalents thereof.

Claims

1. In the method of P-CSCF (proxy - call state control function) entity in IMS-DC (IP (internet protocol) multimedia subsystem-data channel) service, A step of receiving a data channel session connection request message including SDP (session description protocol) offer information from a UE (user equipment), wherein the SDP offer information includes multiplexing support information; A step of determining whether multiplexing is supported based on the above multiplexing support information; and A method characterized by comprising the step of transmitting a request for data stream related information including the multiplexing support information to an IMS-AGW (application gateway) entity.

2. In paragraph 1, A step of receiving the data stream related information based on the multiplexing support information from the IMS-AGW entity; and A step of updating the SDP offer information based on the information related to the data stream; Including the multiplexing support information, A method characterized by information indicating that data streams of multiple applications are supported to be received by a terminal through a single port.

3. In the second paragraph, updating the SDP offer information, A method characterized in that the SDP offer information is updated based on the connection type information of the application included in the SDP offer information to support the above multiplexing.

4. In paragraph 1, A method further comprising: a step of transmitting the updated SDP offer information to an IMS AS (application server); characterized in that the updated SDP offer information is used to update a data channel control policy.

5. In the method of IMS-AGW (application gateway) entity in IMS-DC (IP (internet protocol) multimedia subsystem-data channel) service, A step of receiving a request for data stream related information including multiplexing support information from a P-CSCF (proxy - call state control function) entity; A method characterized in that the above multiplexing support information is based on a data channel session connection request message including SDP (session description protocol) offer information received from a UE (user equipment).

6. In paragraph 5, A step of transmitting the data stream related information based on the multiplexing support information to the P-CSCF entity; The above data stream related information is used to update the SDP offer information received from the UE, and The above multiplexing support information is: A method characterized in that data streams of multiple applications are received by a terminal through a single port.

7. In paragraph 5, the SDP offer information is: A method characterized in that it is updated based on the connection type information of the application included in the above SDP offer information and the information related to the data stream.

8. A method according to claim 6, characterized in that the updated SDP offer information is used to update a data channel control policy.

9. In the IMS-DC (IP (internet protocol) multimedia subsystem-data channel) service, for the P-CSCF (proxy - call state control function) entity, Transmitter and receiver; and comprising at least one processor; wherein the at least one processor comprises: Receive a data channel session connection request message including SDP (session description protocol) offer information from a UE (user equipment), wherein the SDP offer information includes multiplexing support information; Based on the above multiplexing support information, determine whether multiplexing is supported, and A P-CSCF entity configured to transmit a request for data stream related information including the multiplexing support information to an IMS-AGW (application gateway) entity.

10. In the 9th paragraph, at least one processor, configured to receive the data stream related information based on the multiplexing support information from the IMS-AGW entity; A step of updating the SDP offer information based on the information related to the data stream; Including the multiplexing support information, A P-CSCF entity characterized by information indicating that data streams of multiple applications are supported to be received by a terminal through a single port.

11. In paragraph 10, updating the SDP offer information, A P-CSCF entity characterized in that it updates the SDP offer information based on the connection type information of the application included in the SDP offer information to support the above multiplexing.

12. In the 9th paragraph, at least one processor, A P-CSCF entity configured to transmit the updated SDP offer information to an IMS AS (application server), wherein the updated SDP offer information is used to update a data channel control policy.

13. In the IMS-DC (IP (internet protocol) multimedia subsystem-data channel) service, in the IMS-AGW (application gateway) entity, Transmitter and receiver; and comprising at least one processor; wherein the at least one processor comprises: It is configured to receive a request for data stream related information including multiplexing support information from a P-CSCF (proxy - call state control function) entity, An IMS-AGW entity characterized in that the above multiplexing support information is based on a data channel session connection request message including session description protocol (SDP) offer information received from a UE (user equipment).

14. In the 13th paragraph, at least one processor, configured to transmit the data stream related information based on the multiplexing support information to the above P-CSCF entity, The above data stream related information is used to update the SDP offer information received from the UE, The above multiplexing support information indicates that data streams of multiple applications are received by the terminal through one port, and An IMS-AGW entity characterized in that the updated SDP offer information is used to update the data channel control policy.

15. In paragraph 13, the SDP offer information is: An IMS-AGW entity characterized in that it is updated based on the connection type information of the application and the data stream related information included in the above SDP offer information.

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